Saving Data on Android

Transac/ons
Firestore supports another way of writing data, 
transactions
. Transactions are used 
in cases when you want to write a bunch of data to the database at once. While the 
transaction is executing, the user won't be able to read that partially changed state. 
If one of the operations that are executed in a transaction fails, none of them will be 
applied because that could potentially leave the database in an inconsistent and 
undesired state. Either all are applied or none. One transaction operation can write 
to 500 documents maximally.
There is another type of transaction called